1
2
3
4
5
|
You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. Input: (2 -> 4 -> 3) + (5 -> 6 -> 4) Output: 7 -> 0 -> 8 Subscribe to see which companies asked this question |
题意:实际上就是342+465=807然后倒序输出。【一开始也没有看明白。】
参考别人的。一开始题意都没看明白。。。。。。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
/** * Definition for singly-linked list.
* struct ListNode {
* int val;
* struct ListNode *next;
* };
*/
struct ListNode* addTwoNumbers( struct ListNode* l1, struct ListNode* l2) {
struct ListNode *l3 = ( struct ListNode *) malloc ( sizeof ( struct ListNode));
l3->val=0;
l3->next=NULL;
//这边因为l3是一直往后遍历的,所以返回头的话要加个head指示一下。
struct ListNode* head = l3;
l3->val=l1->val+l2->val;
//while循环判断是否申请新的节点
l1=l1->next;
l2=l2->next;
while (l1||l2||l3->val>9){
l3->next=( struct ListNode *) malloc ( sizeof ( struct ListNode));
l3->next->val=0;
l3->next->next=NULL;
if (l1){
l3->next->val+=l1->val;
l1=l1->next;
}
if (l2){
l3->next->val+=l2->val;
l2=l2->next;
}
if (l3->val>9){
l3->next->val+=l3->val/10;
l3->val=l3->val%10;
}
l3=l3->next;
}
return head;
} |
PS:主要是搞清楚有几种情况。9+8这种需要申请节点;12+9这种不等长的;
注意C语言链表的使用。。。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
|
/** * Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
////直接模拟加法就行。先申请一个head
ListNode head= new ListNode( 0 );
int carry= 0 ;
ListNode p1=l1,p2=l2,p3=head;
while (l1!= null || l2!= null ){
if (l1!= null ){
carry+=l1.val;
l1=l1.next;
}
if (l2!= null ){
carry+=l2.val;
l2=l2.next;
}
p3.next= new ListNode(carry% 10 );
p3=p3.next;
carry=carry/ 10 ;
}
if (carry== 1 ){
p3.next= new ListNode( 1 );
}
return head.next;
}
} |
JAVA版本的。
本文转自 努力的C 51CTO博客,原文链接:http://blog.51cto.com/fulin0532/1864621